Novavax Covid-19 vaccine shows 89% efficacy in UK clinical trials

The vaccine of US-based Novavax, a prime contender for use in India, has shown 89.3 per cent efficacy in phase 3 clinical trials conducted in the UK.

Its Indian partner, Serum Institute of India (SII), has applied to the regulator to conduct bridge trials here, and is planning to start manufacturing soon in the country.

The Nasdaq-listed, company said its vaccine candidate NVX-Co-V2373 had met the primary endpoint.

The trial has assessed its efficacy during a period with high transmission and with a new UK strain of the virus. It was conducted in partnership with the British government’s vaccine taskforce. Novavax said the phase 2b trials conducted in South Africa were successful, too.

“With today’s results from our UK phase 3 and South Africa phase 2b clinical trials, we have now reported data on our Covid-19 vaccine from Phase 1, 2 and 3 trials, involving over 20,000 participants. In addition, our PREVENT-19 US and Mexico clinical trial has randomised over 16,000 participants toward our enrolment goal of 30,000,” said Stanley C Erck, president and chief executive officer, Novavax.

The vaccine has not only demonstrated high clinical efficacy but also significant clinical efficacy against both the rapidly emerging UK and South Africa variants, he said.

The UK phase 3 study enrolled more than 15,000 participants in the age group 18-84 (27 per cent of the volunteers were more than 65). The first interim analysis is based on 62 cases, of which 56 cases of Covid-19 were observed in the placebo group against six cases observed in the NVX-CoV2373 group, resulting in a point estimate of vaccine efficacy of 89.3 per cent.

“Preliminary analysis indicates that the UK variant strain that was increasingly prevalent was detected in over 50 per cent of the PCR-confirmed symptomatic cases (32 UK variants, 24 non-variants, 6 unknown),” the company said.

The company in mid-January initiated a rolling submission to the UK’s regulatory agency, the Medicines and Health Products Regulatory Agency. The vaccine is stable at 2-8 degree Celsius and is shipped in a ready-to-use liquid formulation that permits distribution using existing vaccine supply chain channels.

In the South Africa arm, around 60 per cent efficacy was observed for preventing mild, moderate and severe Covid-19 in 94 per cent of the study population that was HIV-negative.

SII to start production of Novavax vaccine in two months

SII, which calls the vaccine Covovax here, has been asked to submit a revised clinical trial protocol before the Subject Expert Committee (SEC).

The SEC has said SII should conduct the proposed study with placebo or other vaccine as the comparator for which “justification is required”. Thus SII has to submit a revised clinical trial protocol before the committee for further deliberation. Besides, SII is gearing up to start making the Novavax vaccine in the next two months, Chief Executive Officer Adar Poonawalla told Business Standard.